Toxicity, Behavioral Effects, and Chitin Structural Chemistry of Reticulitermes flaviceps Exposed to Cymbopogon citratus EO and Its Major Constituent Citral

Abstract

Botanical pesticides are considered the most promising alternative to synthetic pesticides, considering their less negative impacts on the environment and human health. Here, we analyzed the components of lemongrass Cymbopogon citratus essential oil (EO) and evaluated its vapor activity against Reticulitermes flaviceps, in terms of the walking and gripping abilities of workers. In addition, the effects of lemongrass EO and its major component on the cuticular content and structure of chitin in termites were also observed. Our results indicate that cis-citral (36.51%) was the main constituent of lemongrass. In the vapor toxicity assay, the LC50 values of lemongrass EO and citral were 0.328 and 0.177 μL/L, respectively. When worker antennae were treated with lemongrass EO and citral, their walking and gripping capabilities were significantly inhibited. In addition, the cuticular content, thermal stability, and crystallinity of chitin in the termites were decreased after treatment with citral. Collectively, this study provides a basis for developing and utilizing lemongrass and citral as a new environment-friendly insecticide resource to control R. flaviceps.

Termiticidal and Biochemical Activity of Combinatorial Essential Oil Ingredients of <i>Tagetes erecta</i> on Indian White Termite <i>Odontotermes obesus</i>

“…Lemongrass essential oil and its major components dissolute cuticle and chitin in termites. Both lemongrass and citral were found safe to control R. flaviceps [34]. Similar anti-termite activity was reported in subterranean termites [35].…”

Biochemical Alterations and Termiticidal Activity of Combinatorial Essential Oil Ingredients of <i>Citrus maxima</i> on Indian White Termite <i>Odontotermes obesus</i>

“…Botanical pesticides showed less negative impacts on the environment and human health. Lemongrass and citral are more effective against R. flaviceps [44].…”

Mentha spp. Essential Oils: A Potential Toxic Fumigant with Inhibition of Acetylcholinesterase Activity on Reticulitermes dabieshanensis

“…Essential oils are characterized by being easily volatile, having low residuality, and having multiple modes of action, making them often considered substitutes for chemical pesticides. They can effectively control pests in small-scale agricultural systems [2,24]. Menthas are famous spices widely used in food, beverages, pharmaceuticals, and cosmetics for their valuable EOs.…”

“…Termites comprise a group of social wood-feeding cockroaches with over 3000 species [1]. These pests are a significant threat to agriculture and forestry in tropical and subtropical regions and can cause extensive economic and social harm [2]. Reticulitermes flaviceps is responsible for causing serious damage to agriculture and forestry in China [3].…”